Electronic whiteboards and blackboards—in general electronic boards—are known that are configured to detect the position of a pointing device—a stylus—such as a marking pointing device, e.g., a marking stylus, or a non-marking stylus, and, for example, collect coordinate information for use in a computer to track the location over time. One class of such electronic boards uses a set of sensors close to the surface with known geometric relationship to each other, and a pointing device that emits energy detectable by the sensors. A similar technology uses a set of transmitters close to the surface with known geometric relationship to each other, and a pointing device that includes one or more sensors that are able to detect energy emitted by the transmitters.
Luidia, Inc., of San Carlos, Calif. makes a location determining apparatus called eBeam™ that includes a device that attaches to a substantially planar surface and that includes two ultrasound sensors at known geometric relationship to each other, an infrared sensor, analog electronics coupled to the sensors, and a digitizer to convert the analog waveforms from the sensors to digital waveforms. The device can thus detect ultrasound and also detect infrared. A pointing device used as a pointing stylus or with a marking functionality as a marking stylus includes an ultrasound transmitter and an infrared transmitter that when triggered, e.g., by touching the surface or being close to the surface, emits pulses of infrared and of ultrasound. The infrared travels much faster than the ultrasound. Detection of each infrared pulse forms a time mark. Each ultrasound pulse travels via two paths to the two respective ultrasound sensors. The device is configured to digitally detect features of each ultrasound waveform sensed to determine the time of arrival. The device is configured to use this information to determine the location of the pointing device when the pointing device is activated, e.g., when it is close to the surface. The device thus is configured to determine events that include the two-dimensional coordinates of the tip of the pointing device, e.g., when at or close to the surface in the case of such triggering. The pointing device may be in the form of a cover for a felt-tip pen or be a non-marking pointer, and include buttons that when activated cause a computer coupled to the device to carry out one or more actions.
Such a surface together with such a location determining apparatus may also be used to project an image thereon, e.g., using a projector interfaced to a computer. The pointing device can then be used as a virtual “pen” to mark up the projected surface. The pointing device can also be used in the same manner as a computer pointing device such as a mouse. Buttons on the pointing device can be used, for example, in the same manner as mouse buttons.
U.S. Pat. No. 6,266,051 to Holtzman (the Holtzman arrangement) describes retrofittable apparatus for converting a substantially planar surface into an electronic data capture device, in which the components of the apparatus are readily retrofittable to a wide variety of otherwise conventional writing-surface structures, such as whiteboards. Triangulation techniques are used to track the position and motion of a writer or eraser. An encoding facility associated with the pointing implement provides the ability to distinguish whether the implement is used for marking or erasing, and also may determine the nature or character of written line width or eraser swath. A data stream thus generated can be used in a variety of ways, such as for example, to feed information into the memory of a digital computer, and/or to feed information for transmission to remote stations.
Although the Holtzman apparatus provides a mechanism for retrofitting an electronic data capture function to an otherwise ordinary writing surface, the inventors recognize that many elements of a transcription apparatus are inexpensive and can be pre-assembled in components such as whiteboards and projectors and displays, such that, after sale of such a component, the device can easily be upgraded, and can avoid such questions as positioning of sensors and/or calibration. Furthermore, having an apparatus that is easily upgradable may providing a source of additional revenue by providing or licensing others to provide modules that easily upgrade the device.
It further would be advantageous to provide an electronic apparatus that adapts a writing surface such as standard whiteboard into an electronic transcription apparatus that is functional to determine the location of a pointing device, wherein the adapting avoids the use of temporary fasteners and other such expedients.